Patents:
Impermissible recapture under 35 U.S.C. §251 is not implicated unless a patentee attempts to regain subject matter deliberately surrendered during the original patent prosecution.

For full opinion:
2011 U.S.App.LEXIS 18125
2011 WL 3862645

Opinion (Lourie): The United States District Court for the Middle District of Tennessee invalidated U.S. Patent RE39,998 ("RE'998") held by Magotteaux International S/A and Magotteaux, Inc. (together "Magotteaux"). The district court found that Magotteaux had surrendered subject matter during reissue examination and was barred from recapturing that broader subject matter by 35 U.S.C. §251. The Court of Appeals for the Federal Circuit ruled that Magotteaux acted as its own lexicographer and "although 'solid solution' has an ordinary meaning in the art, the patentee here chose instead to apply a special meaning to the term." Additionally, the court used extrinsic expert testimony to render the plaintiff, AIA Engineering's ("AIA"), proposed claim construction physically impossible. Where "the specification reveals a special meaning for a term that differs from the meaning it might otherwise possess, that special meaning governs, particularly when it also serves to avoid an inoperable claim construction." Thus, the district court's claim construction was erroneous because "homogenous solid solution" and "homogenous ceramic composite" were synonymous within the original patent and RE'998; the "reissue prosecution did not broaden the claims." Without broadening, summary judgment under §251 was improper, therefore the case was REVERSED and REMANDED.